Sea to Summit 1Pin Ladderlock Field Repair Buckle

The Ladder Lock Field Repair Buckle is an easy-to-use and more permanent solution for broken or worn-out buckles. The clever design allows you to repair broken buckles, using only a screwdriver. And - because the buckles are secured by a stainless steel screw, there's no need (unlike temporary repair buckles) to replace them with sewn-on buckles on your return. 

Sizing = Buckle strap width.